ISP Draft EIR/S: Sample Impact Table

Draft Programmatic Environmental Impact Statement/Environmental Impact Report
San Francisco Estuary Invasive Spartina Project: Spartina Control Program
April 2003

Table 3.1-1: Summary of Potential Hydrologic and Geomorphic Effects
GEO-1: Erosion or deposition of sediment at sites of cordgrass eradication.	All Alternatives: Minor erosion and sedimentation.	All Alternatives: Potentially significant erosion.	All Alternatives: Minor erosion potential.	All Alternatives: Potentially significant erosion from diking activities.	All Alternatives: Minimal erosion potential.	All Alternatives: Minor erosion potential.	Alternatives 1, 2: Beneficial effect on sediment transport in tidal creeks, mudflats, marshes, and channels.
GEO-2: Erosion or topographic change of marsh and mudflat by vehicles used in eradication.	All Alternatives: Minor impact from access.	All Alternatives: Potentially significant microtopographic changes and erosion from use of vehicles in marshes.	All Alternatives: Minor impact from access.	All Alternatives: Potentially significant topographic changes from diking activities.	All Alternatives: Minor impact from access.	All Alternatives: Minor impact from access.	N/A
GEO-3: Remobilization of sand in cordgrass-stabilized estuarine beaches.	All Alternatives: Minor increased beach erosion and sedimentation.	All Alternatives: Potentially significant erosion.	All Alternatives: No impact.	All Alternatives: Potentially significant beach erosion.	All Alternatives: Potentially significant beach erosion.	All Alternatives: Potentially significant beach erosion.	Alternatives 1,2: Long-term benefit of establishment of beaches. Alternative 3: Short-term benefit to beach restoration, no long-term benefit.
GEO-4: Increased demand for sediment disposal and potential spread of invasive cordgrass via sediment disposal.	All Alternatives: No impact.	All Alternatives: Potentially significant impacts related to disposal of dredged sediments and inadvertent dispersal of invasive cordgrass via disposed sediments.	All Alternatives: No impact.	All Alternatives: No impact.	All Alternatives: No impact.	All Alternatives: No impact.	All Alternatives: No impact.
GEO-5: Increased volume and velocity of tidal currents in channels due to the remoal of invasive cordgrass.	All Alternatives: Minor impact from localized clearing.	All Alternatives: Potential increase in erosion from increased tidal velocities/currents.	All Alternatives: No impact.	All Alternatives: Potential increase in erosion from increased tidal velocities/currents.	All Alternatives: Potential increase in erosion from increased tidal velocities/ currents.	All Alternatives: Potential increase in erosion from increased tidal velocities/currents.	All Alternatives: Beneficial effect on tidal channel and creek flows.
GEO-6: Increased depth and turbulence of tidewaters impounded in salt marsh pans.	All Alternatives: No adverse impacts. .	All Alternatives: No adverse impacts.	All Alternatives: No adverse impacts.	All Alternatives: No adverse impacts.	All Alternatives: No adverse impacts.	All Alternatives: No adverse impacts.	Alternatives 1, 2: Permanent beneficial effect. Alternative 3: Temporary beneficial effect.

Table 3.1-1: Summary of Potential Hydrologic and Geomorphic Effects

Impact

Manual Removal
(Hand pulling and manual
excavation)

Mechanical
Removal
(Excavation, dredging, and shredding)

Pruning, Hand-mowing, and Smothering

Flooding
(Diking, drowning, and salinity
variation)

Burning

Herbicide
Application

Beneficial Effects

GEO-1: Erosion or deposition of sediment at sites of cordgrass
eradication.

All Alternatives:
Minor erosion and sedimentation.

All Alternatives:
Potentially
significant erosion.

All Alternatives: Minor erosion
potential.

All Alternatives:
Potentially
significant erosion from diking
activities.

All Alternatives: Minimal erosion potential.

All Alternatives:
Minor erosion
potential.

Alternatives 1, 2: Beneficial effect on sediment transport in tidal creeks, mudflats, marshes, and channels.

GEO-2: Erosion or topographic change of marsh and mudflat by vehicles used in eradication.

All Alternatives:
Minor impact from access.

All Alternatives:
Potentially
significant
microtopographic changes and
erosion from use
of vehicles in marshes.

All Alternatives:
Minor impact from access.

All Alternatives:
Potentially
significant
topographic changes from
diking activities.

All Alternatives:
Minor impact from access.

N/A

GEO-3: Remobilization of sand in cordgrass-stabilized
estuarine beaches.

All Alternatives:
Minor increased beach erosion and sedimentation.

All Alternatives:
Potentially significant erosion.

All Alternatives:
No impact.

All Alternatives:
Potentially significant beach erosion.

Alternatives 1,2:
Long-term
benefit of establishment
of beaches.

Alternative 3:
Short-term
benefit to beach
restoration, no
long-term benefit.

GEO-4: Increased demand for sediment disposal and potential spread of invasive cordgrass via sediment
disposal.

All Alternatives:
No impact.

All Alternatives:
Potentially
significant impacts related to disposal of dredged
sediments and inadvertent
dispersal of
invasive cordgrass via disposed
sediments.

All Alternatives:
No impact.

GEO-5: Increased volume and velocity of tidal currents in channels
due to the remoal of invasive cordgrass.

All Alternatives:
Minor impact from localized clearing.

All Alternatives:
Potential increase in erosion from increased tidal velocities/currents.

All Alternatives:
No impact.

All Alternatives:
Potential increase in erosion from increased tidal velocities/currents.

All Alternatives: Potential increase in erosion from increased tidal velocities/ currents.

All Alternatives:
Potential increase in erosion from increased tidal velocities/currents.

All Alternatives:
Beneficial effect on tidal channel and creek flows.

GEO-6: Increased depth and turbulence of tidewaters impounded in salt marsh pans.

All Alternatives:
No adverse
impacts.

Alternatives 1, 2:
Permanent
beneficial effect.

Alternative 3:
Temporary
beneficial effect.